Proteinaceous Inhibitor Versus Fructose as Modulators of Pteris deflexa Invertase Activity

An acid invertase from the fern Pteris deflexa Link was purified and the effect of reaction products on enzyme activity was studied. Fructose and glucose were competitive and non-competitive inhibitors of the enzyme, respectively. Since proteins suppressed glucose and fructose inhibition of the enzyme, an invertase modulation by reaction products is unlikely; nevertheless, an invertase proteinaceous inhibitor previously reported could have a role in this respect. The purified enzyme was an heterodimer M r 90,000 Daltons composed of subunits of 66,000 and 30,000 Daltons. The enzyme had β -fructofuranosidase activity and hydrolyzed mainly sucrose but also raffinose and stachyose, with K m of 3.22, 10.80 and 38.50 mM, respectively. Invertase activity with an optimum pH at 5.0 was present in almost every leaf fern tissue. Pinnas (sporophyll leaflets) had the higher enzyme levels. Invertase histochemical and immunochemical localization studies showed the enzyme mainly in phloem cells. Epidermis, collenchyma and parenchyma cells also showed invertase protein.     

Potential antifouling strategies for marine finfish aquaculture: the effects of physical and chemical treatments on the settlement and survival of the hydroid Ectopleura larynx

The hydroid Ectopleura larynx is a common fouling organism on aquaculture nets. To contribute to the development of novel cleaning methods, laboratory and field studies determined the effects of heat (30, 40, 50 and 60°C for immersion times of 1 and 3 s) and acetic acid (0.2 and 2.0% for immersion times of 1, 3 and 10 s, 1 and 5 min) on the settlement of actinulae and the survival of juvenile and adult E. larynx. Laboratory studies showed that, regardless of immersion time, a temperature of 50°C was effective in preventing the settlement of actinulae and the survival of juveniles, while ≤12% of adult hydroids could survive. A temperature of 60°C killed all adult hydroids. For an acetic acid concentration of 0.2%, an immersion time of 1 min substantially reduced the settlement of actinulae and the survival of juvenile and adult hydroids, and none of the juvenile and adult hydroids survived after 5 min. For an acetic acid concentration of 2.0%, all immersion times were effective and reduced the mean settlement of actinulae and the survival of juvenile and adult hydroids to ≤10%. Field studies with fouled net panels exposed to selected heat or acetic acid treatments showed small reductions in mean wet weight and net aperture occlusion of the net panels 2 and 5 days after treatment. Visual inspections of the net panels showed that hydranths of the hydroids were shed, but the dead stolons of the hydroids remained on the treated net panels. Novel cleaning methods and devices may utilise these results to effectively kill E. larynx on aquaculture nets, while further studies are needed to determine the necessity of removing the dead hydroids before further biofouling accumulates on thenets.     

Shifts in Antarctic megabenthic structure after ice-shelf disintegration in the Larsen area east of the Antarctic Peninsula

The aim of this study was to contribute to a general understanding of the response of the Antarctic macrobenthos to environmental variability and climate-induced changes. The change in population size of selected macrobenthic organisms was investigated in the Larsen A area east of the Antarctic Peninsula in 2007 and 2011 using ROV-based imaging methods. The results were complemented by data from the Larsen B collected in 2007 to allow a conceptual reconstruction of the environment-driven changes before the period of investigation. Both Larsen areas are characterised by ice-shelf disintegration in 1995 and 2002, respectively, as well as high inter-annual variability in sea-ice cover and oceanographic conditions. In 2007 one ascidian species, Molgula pedunculata, was abundant north and south of the stripe of remaining ice shelf between Larsen A and B. Population densities decreased drastically in the Larsen A between 2007 and 2011, coincident with the decrease in Corella eumyota, another ascidian. Among the ophiuroids, the population of deposit feeders increased, while suspension feeders halved their abundance. Current measurements indicated a northward flow between the Larsen B and Larsen A, suggesting that a major physical forcing on benthic population development comes from the South. The results demonstrate that Antarctic macrobenthic populations can exhibit dramatic population dynamics. Analyses of sea-ice dynamics, salinity, temperature and surprisingly ice-shelf disintegration history, however, did not provide any clear evidence for environmental drivers underlying the apparent changes.     

Short-term disturbance by a commercial two-dimensional seismic survey does not lead to long-term displacement of harbour porpoises

Assessments of the impact of offshore energy developments are constrained because it is not known whether fine-scale behavioural responses to noise lead to broader-scale displacement of protected small cetaceans. We used passive acoustic monitoring and digital aerial surveys to study changes in the occurrence of harbour porpoises across a 2000 km² study area during a commercial two-dimensional seismic survey in the North Sea. Acoustic and visual data provided evidence of group responses to airgun noise from the 470 cu inch array over ranges of 5–10 km, at received peak-to-peak sound pressure levels of 165–172 dB re 1 µPa and sound exposure levels (SELs) of 145–151 dB re 1 µPa² s⁻¹. However, animals were typically detected again at affected sites within a few hours, and the level of response declined through the 10 day survey. Overall, acoustic detections decreased significantly during the survey period in the impact area compared with a control area, but this effect was small in relation to natural variation. These results demonstrate that prolonged seismic survey noise did not lead to broader-scale displacement into suboptimal or higher-risk habitats, and suggest that impact assessments should focus on sublethal effects resulting from changes in foraging performance of animals within affected sites.     

Behavioural Risk Factors in Mid-Life Associated with Successful Ageing,Disability, Dementia and Frailty in Later Life: A Rapid Systematic Review

Background

Smoking, alcohol consumption, poor diet and low levels of physical activity significantly contribute to the burden of illness in developed countries. Whilst the links between specific and multiple risk behaviours and individual chronic conditions are well documented, the impact of these behaviours in mid-life across a range of later life outcomes has yet to be comprehensively assessed. This review aimed to provide an overview of behavioural risk factors in mid-life that are associated with successful ageing and the primary prevention or delay of disability, dementia, frailty and non-communicable chronic conditions.

Methods

A literature search was conducted to identify cohort studies published in English since 2000 up to Dec 2014. Multivariate analyses and a minimum follow-up of five years were required for inclusion. Two reviewers screened titles, abstracts and papers independently. Studies were assessed for quality. Evidence was synthesised by mid-life behavioural risk for a range of late life outcomes.

Findings

This search located 10,338 individual references, of which 164 are included in this review. Follow-up data ranged from five years to 36 years. Outcomes include dementia, frailty, disability and cardiovascular disease. There is consistent evidence of beneficial associations between mid-life physical activity, healthy ageing and disease outcomes. Across all populations studied there is consistent evidence that mid-life smoking has a detrimental effect on health. Evidence specific to alcohol consumption was mixed. Limited, but supportive, evidence was available relating specifically to mid-life diet, leisure and social activities or health inequalities.

Conclusions

There is consistent evidence of associations between mid-life behaviours and a range of late life outcomes. The promotion of physical activity, healthy diet and smoking cessation in all mid-life populations should be encouraged for successful ageing and the prevention of disability and chronic disease.     

Endothelin in the middle cerebral artery: a case of multiple system atrophy

In this study, we show the changes in the wall of the middle cerebral artery of a subject who suffered multiple system atrophy with autonomic failure. An electron-immunocytochemical approach was employed to reveal the presence of endothelin-1. Our results demonstrate the presence of immunoreactive endothelin-1 in the endothelial cells of the intima, vascular smooth muscle cells and macrophages of the media and neointima, and perivascular nerves/axons varicosities at the adventitial-medial border of the artery. It is concluded that endothelin-1 may, therefore, play a number of roles within diseased cerebral artery. The finding of endothelin-1-positive varicosities of autonomic innervation to this artery suggests an influence of neural endothelin on vascular smooth muscle in multiple system atrophy with autonomic failure. However, the presence of features such as neointima formation, wall irregularities and foam cells suggest the coexistence of atherosclerosis.     

Inhibition of hydrolytic enzyme activities and plant pathogen growth by invertase inhibitors

The invertase inhibitory protein isolated from Cyphomandra betacea Sendt and Solanum tuberosum inhibited the invertase activity from different species, genera and even plant family. Furthermore, proteinaceous inhibitors are not invertase specific; fungal, bacterial and higher plant enzymes including polygalacturonase, pectinase, pectin lyase, alpha-L-arabinofuranosidase and beta-glucosidase are also shown to be inhibited. Both inhibitors exhibited an in vitro antibacterial action against phytopathogenics strains of Xanthomonas campestris pvar vesicatoria CECT 792, Pseudomonas solanacearum CECT 125, Pseudomonas corrugata CECT 124, Pseudomonas syringae and Erwinia carotovora var carotovora.     

Invertase proteinaceous inhibitor of Cyphomandra betacea Sendt fruits

This work describes a new invertase proteinaceous inhibitor from Cyphomandra betacea Sendt. (tomate de arbol) fruits. The proteinaceous inhibitor was isolated and purified from a cell wall preparation. The pH stability, kinetics of the inhibition of the C. betacea invertase, inhibition of several higher plant invertases and lectin nature of the inhibitor were studied. The inhibitor structure involves a single polypeptide (Mr = 19000), as shown by gel filtration and SDS-PAGE determinations. N-terminal aminoacid sequence was determined. The properties and some structural features of the inhibitor are compared with the proteinaceous inhibitors from several plant species (Beta vulgaris L., Ipomoea batatas L. and Lycopersicon esculentum Mill.). All these inhibitors share lectinic properties, some common epitopes, some aminoacid sequences and a certain lack of specificity towards invertases of different species, genera and even plant family. In consequence, the inhibitors appear to belong to the same lectin family. It is now known that some lectins are part of the defence mechanism of higher plants against fungi and bacteria and this is a probable role of the proteinaceous inhibitors.